Thinking Headways.
Am I right to think that 3 packs of 15 headways (48V) will give me 24Ah are enough power to get me to work and back. Round trip is 15Km. Can I get away with 2 packs of 15 @ 16Ah? I'm not really clear on the calculations, but I based this estimation on Richo's comment in Soyachip's FZR250 thread.

Ideally, I would like to be able to do 100Km/h, but hope I can set this up with gearing via chain cogs.

I may have gone a bit big on the motor, but believe I can detune it with the SR controller?

PS. I'm a noob. Car Mechanic, Classic scooter enthusiast, and think I have a basic understanding of electronics.

Last edited by Rolf on Mon, 08 Jul 2019, 14:53, edited 1 time in total.

I'll check on how much space I have and see if I can fit 4 packs in, unless there is a better suggestion on which batteries to use?

So max continuous current is 72A? (Based on 48V and 3500W) Once it runs, I'll play with the gearing with an amp meter connected if this makes sense. I find that with only weighing 70Kg, I can get more speed out of ICE scooters than my friends.

But if I can cruise at 65km/h, then That will do. I was hoping for more, but as a first project, I was wanting to keep it at 48V for safety reasons. My understanding is that speed is relative to voltage. Is this correct?

Now if you bought the higher voltage controller and the pack wasn't quite big enough you could just put a few extra in series.
No need to parallel the pack at all.
And you would then also get a increase in your continuous speed.

Help prevent road rage - get outta my way! Blasphemy is a swear word. Magnetic North is a south Pole.

I already have the controller
I started this project almost two years ago and got sidetracked. A bit has changed in what’s available since then. Back then, I did do all the calculations for gearing and set it up to do a bit over 100km/h at full RPM. I know it may seem a lot for a scooter with 12 inch tyres, but my main ride is a 1959 Vespa that has had it’s engine kitted up to do 120km/h on 10 inch wheels!

Thanks for pointing out about not using separate packs. Makes sense. Did I mention I’m a noob?

I did read up on LTO’s and they seem heavy for the output. But is it true that they are so stable that they don’t need a BMS. I read that somewhere on the internet and, well, everything on the internet is true! Not that I don’t want to learn how to set up a BMS.

I also researched Nissan Leaf cells and like the idea. I’ll check on the weekend if I can fit them into the space. How hard are they to source?

As for the overall project, I’m more concerned with the outcome rather than the cost.

I suggest getting some cardboard or foam and mocking up the motor in place.
Then you can see how much room is left for batteries.
I'd suspect this will determine what batteries you can use and how many.

Help prevent road rage - get outta my way! Blasphemy is a swear word. Magnetic North is a south Pole.

Yes, the controller isn't fully mounted, but that's where I plan for it to go. Plenty of battery space above. Still looking for the best power to weight battery pack I can put in. There isn't that much difference between the LTOs you mentioned and Headways. (Assuming I calculated correctly)

I checked out to see if I could fit 20 LTOs in. Turns out that they are about the size of an aerosol can. After failing to see how they could fit by measuring, I found 20 aerosols cans to see if I could jam them in. I was three short, and the other 17 were a squeeze.

I have ordered enough headway cells to make a 30Ah 48V pack to get me going. I may look at the LG batteries in the future, depending on how my current draw pans out. I received a 48V to 12V 120W converter this week. I also have a cycle analyst on the way. It’s all moving forward.

I have a future project in mind that I can move the headway cells to, but that’s a different story.